The herein disclosed inventive concepts relate to the field of articulating arms for supporting devices, for example electronic displays (e.g. monitors).
Existing articulating arms use a spring or gas cylinder connected to the arm to provide a counterbalance force thereto, so as to support the mass of the articulating arm and any devices attached thereto (e.g. an electronic display) throughout the positional range of the arm. Many known articulating arms are configured to support a device of a known mass or a very narrow range of masses. Some of these known arms use a coiled spring having a fixed uniform spring rate. In these arms, adjustment of the coiled spring assembly can prove difficult, and it may not be possible to swap between devices of varying mass without changing the internal components of the articulating arm, e.g. the spring, which is both a costly and time-consuming process.
An additional problem relating to coiled spring assemblies is that it may be difficult for them to properly accommodate the combined mass of the arm and the attached device as the articulating arm moves through its range of angular positions. The multitude of individual angular positions of the arm within its range of angular positions can place greatly different counterbalance requirements on the coiled spring assembly, and these counterbalance requirements typically change dynamically as the articulating arm is positioned through said range of angular positions. Because standard coiled springs have a linear force response as they are elongated or compressed, known articulating arms employing coiled springs alone as the counterbalance-force providing means are unable to properly replicate the approximate counterbalance force needed to support the articulating arm (and any device attached thereto) throughout its positional range.
Recent efforts to address this issue have included employing a pivotable clevis member connected to a gas cylinder, the pivotable clevis assembly acting to dynamically adjust the counterbalance force provided by the gas cylinder to the articulating arm as it is positioned throughout its range of angular positions. U.S. patent application Ser. No. 11/544,076, filed Oct. 6, 2006 and entitled “EXTENSION ARM WITH MOVING CLEVIS,” which is incorporated herein by reference as if fully set forth, discloses an exemplary pivotable clevis assembly. Some drawbacks of a continued reliance on the use of gas cylinders include that they are both costly and prone to failure, and that placement of the gas cylinder within the arm limits the ability to decrease the overall size of the articulating arm. Further, gas cylinders lose strength over time, and therefore must be periodically replaced. Moreover, the use of a pivotable clevis member adds an additional amount to the overall cost of producing the articulating arm.
Further, as electronic displays have become smaller and lighter, it is desirable to produce articulating arms having slimmer profiles, for example for aesthetic purposes. Reducing the size and weight of an articulating arm also reduces the cost of producing said arms, due to material costs savings. Maintenance of the spring or gas cylinder within an articulating arm limits the potential for reducing the size of the articulating arm.
Therefore, new extension arm assemblies which overcome these and other problems are desired.